Enhanced 2-O-α-d-Glucopyranosyl-l-ascorbic Acid Synthesis through Iterative Saturation Mutagenesis of Acceptor Subsite Residues in Bacillus stearothermophilus NO2 Cyclodextrin Glycosyltransferase

2018 ◽  
Vol 66 (34) ◽  
pp. 9052-9060 ◽  
Author(s):  
Xiumei Tao ◽  
Tian Wang ◽  
Lingqia Su ◽  
Jing Wu
Keyword(s):  
Ascorbic Acid ◽  
Bacillus Stearothermophilus ◽  
Acid Synthesis ◽  
Saturation Mutagenesis ◽  
Cyclodextrin Glycosyltransferase ◽  
Ascorbic Acid Synthesis ◽  
Iterative Saturation Mutagenesis

scholarly journals Iterative Saturation Mutagenesis of −6 Subsite Residues in Cyclodextrin Glycosyltransferase from Paenibacillus macerans To Improve Maltodextrin Specificity for 2-O-d-Glucopyranosyl-l-Ascorbic Acid Synthesis

2013 ◽  
Vol 79 (24) ◽  
pp. 7562-7568 ◽  
Author(s):  
Ruizhi Han ◽  
Long Liu ◽  
Hyun-dong Shin ◽  
Rachel R. Chen ◽  
Jianghua Li ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Substrate Binding ◽  
Acid Synthesis ◽  
Saturation Mutagenesis ◽  
Wild Type ◽  
Cyclodextrin Glycosyltransferase ◽  
Content Type ◽  
Paenibacillus Macerans ◽  
Ascorbic Acid Synthesis ◽  
Iterative Saturation Mutagenesis

ABSTRACT2-O-d-Glucopyranosyl-l-ascorbic acid (AA-2G), a stablel-ascorbic acid derivative, is usually synthesized by cyclodextrin glycosyltransferase (CGTase), which contains nine substrate-binding subsites (from +2 to −7). In this study, iterative saturation mutagenesis (ISM) was performed on the −6 subsite residues (Y167, G179, G180, and N193) in the CGTase fromPaenibacillus maceransto improve its specificity for maltodextrin, which is a cheap and easily soluble glycosyl donor for AA-2G synthesis. Site saturation mutagenesis of four sites—Y167, G179, G180, and N193—was first performed and revealed that four mutants—Y167S, G179R, N193R, and G180R—produced AA-2G yields higher than those of other mutant and wild-type CGTases. ISM was then conducted with the best positive mutant as a template. Under optimal conditions, mutant Y167S/G179K/N193R/G180R produced the highest AA-2G titer of 2.12 g/liter, which was 84% higher than that (1.15 g/liter) produced by the wild-type CGTase. Kinetics analysis of AA-2G synthesis using mutant CGTases confirmed the enhanced maltodextrin specificity and showed that compared to the wild-type CGTase, the mutants had no cyclization activity but high hydrolysis and disproportionation activities. A possible mechanism for the enhanced substrate specificity was also analyzed through structure modeling of the mutant and wild-type CGTases. These results indicated that the −6 subsite played crucial roles in the substrate binding and catalytic reactions of CGTase and that the obtained CGTase mutants, especially Y167S/G179K/N193R/G180R, are promising starting points for further development through protein engineering.

scholarly journals The Myo ‐inositol pathway does not contribute to ascorbic acid synthesis

Plant Biology ◽  
2018 ◽  
Vol 21 (S1) ◽  
pp. 95-102 ◽  
Author(s):  
E. Ivanov Kavkova ◽  
C. Blöchl ◽  
R. Tenhaken
Keyword(s):  
Ascorbic Acid ◽  
Acid Synthesis ◽  
Ascorbic Acid Synthesis

Ascorbic Acid Synthesis with the Reconstructed Enzyme System

1961 ◽  
Vol 50 (4) ◽  
pp. 374-375 ◽  
Author(s):  
KAZUO YAMADA ◽  
KANTARO SUZUKI ◽  
YOSHITAKE MANO ◽  
NORIO SHIMAZONO
Keyword(s):  
Ascorbic Acid ◽  
Enzyme System ◽  
Acid Synthesis ◽  
Ascorbic Acid Synthesis

scholarly journals Ascorbic Acid Synthesis in Fetal and Neonatal Pigs and in Pregnant and Postpartum Sows

2001 ◽  
Vol 131 (7) ◽  
pp. 1997-2001 ◽  
Author(s):  
San Ching ◽  
Donald C. Mahan ◽  
Joseph S. Ottobre ◽  
Konrad Dabrowski
Keyword(s):  
Ascorbic Acid ◽  
Acid Synthesis ◽  
Neonatal Pigs ◽  
Ascorbic Acid Synthesis

Ascorbic acid synthesis is stimulated by enhaced glyeogenoiysls in murine liver

1995 ◽  
Vol 78 ◽  
pp. 22
Author(s):  
L. Braun ◽  
M. Csala ◽  
G. Bánhegyi ◽  
T. Garzó ◽  
J. Mandl
Keyword(s):  
Ascorbic Acid ◽  
Acid Synthesis ◽  
Murine Liver ◽  
Ascorbic Acid Synthesis

scholarly journals Erratum to: Rice GDP-mannose pyrophosphorylase OsVTC1-1 and OsVTC1-3 play different roles in ascorbic acid synthesis

2016 ◽  
Vol 90 (4-5) ◽  
pp. 533-533
Author(s):  
Hua Qin ◽  
Zaian Deng ◽  
Chuanyu Zhang ◽  
Yayun Wang ◽  
Juan Wang ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Acid Synthesis ◽  
Ascorbic Acid Synthesis
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